This invention concerns a device to be used in connection with mechanical seals meant to seal the lead-in of a rotating shaft between two rooms containing different media.
Mechanical seals are often used in submersible electrically operated machines, such as pumps, turbines and mixers, to seal the driving shaft between driving unit and hydraulic unit, the shaft normally going through an oil room between the units. The seals, one between driving unit and oil room and one between oil room and hydraulic unit, contain one rotating and one non-rotating seal ring which are pressed towards each other by spring force.
The spring force must be relatively strong to secure a good sealing. Lubricant must be brought continuously to the contact surfaces. Oil is usually used as the lubricant which is contained in the oil housing.
In a submersible pump of a conventional type where the driving unit is arranged on top of the pump housing, there is normally no problem bringing lubricant to the seals since these are usually covered by the oil in the oil housing. If the driving unit is arranged under or beside the hydraulic unit, problems with bringing the oil to the seals may occur.
A way to solve this problem is to arrange a pumping device of some sort to bring oil up to the upper seal (Swedish Pat. No. 7401606-4). This known device does not however function if the driving shaft takes an essentially horizontal position.